#! /usr/bin/python3

import rospy # 声明一个ros节点
from std_msgs.msg import String # 引用字符串

# 定义话题节点
def talker():
    pub = rospy.Publisher('chatter', String, queue_size=10)
    rospy.init_node("talker", anonymous=True)
    rate = rospy.Rate(10) # 循环频率10hz
    while not rospy.is_shutdown():
        hello_str = "hello world %s" % rospy.get_time()
        rospy.loginfo(hello_str)
        pub.publish(hello_str) # 将字符串内容发布到话题中
        rate.sleep()

if __name__ == "__main__":
    try:
        talker()
    except rospy.ROSInternalException:
        pass
